Pierluigi Paganini February 19, 2020

The Cybersecurity and Infrastructure Security Agency (CISA) is warning critical U.S. infrastructure operators of a recent ransomware attack that affected a natural gas compression facility.

The Cybersecurity and Infrastructure Security Agency (CISA) issued an alert across critical U.S. infrastructure sectors about a recent infection at a natural gas compression facility.

“The Cybersecurity and Infrastructure Security Agency (CISA) responded to a cyberattack affecting control and communication assets on the operational technology (OT) network of a natural gas compression facility. A cyber threat actor used a Spearphishing Link [T1192] to obtain initial access to the organization’s information technology (IT) network before pivoting to its OT network.” reads the alert published by CISA. “The threat actor then deployed commodity ransomware to Encrypt Data for Impact [T1486] on both networks. Specific assets experiencing a Loss of Availability [T826] on the OT network included human machine interfaces (HMIs), data historians, and polling servers.”

Attackers initially launched a spear-phishing attack to infiltrate the target network, then pivoted to the OT network. This was possible because the victim failed to implement segmentation between the IT and OT networks. Then the attackers deployed ransomware that encrypted files on both IT and OT networks causing the “loss of availability” of human-machine interfaces (HMIs), data historians, and polling servers.

Once the networks have been infected with the ransomware, internal assets were no longer able to read and aggregate real-time operational data reported from low-level OT devices, causing a partial Loss of View for human operators.

According to the alerts, the infection did not impact any programmable logic controllers (PLCs) on the affected networks because the malware was designed to infect only Windows devices and the organization did not lose control of operations at any point during the attack.

In response to the incident, the target organization decided to implement a deliberate and controlled shutdown of the operations for approximately two days. The incident resulted in a Loss of Productivity and Revenue, after which normal operations resumed.

CISA alert provided planning and operational mitigation measures, as well as technical and architectural mitigations that should be implemented by organizations in critical infrastructure sectors to avoid similar ransomware attacks.

“The victim was able to obtain replacement equipment and load last-known-good configurations to facilitate the recovery process.” continues the report. “All OT assets directly impacted by the attack were limited to a single geographic facility.”

The targeted org was able to get replacement equipment following this ransomware incident and to load last-known-good configurations that made it easier to recover after the attack.

CISA officials confirmed that the threat actor has never obtained the ability to control or manipulate operations during the attack.

Although the attack had a limited direct impact on operations to one control facility, geographically distinct compression facilities also had to halt operations because of pipeline transmission dependencies. The cyberattack resulted in an operational shutdown of the entire pipeline asset for approximately two days.

Pierluigi Paganini

(SecurityAffairs – hacking, ransomware)

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